Frost on inside coop door & floor

I know there is a similar post below this but my specific question is what can I do to minimize or release excess humidity in negative degree temps? What % humidity is considered dangerous? I have core drilled holes in the tops of the coop but still get condensation/frost on the door which is all windows. also, the bedding (shavings) seems to get damp and frozen to the vinyl floor. Just trying to think of ways to release this extra humidity so the 12 chooks don't get frostbite, have been applying vaseline at night. My coop is 8'x8'x8' and has 12 chickens. no heat/electric. Thank you for any and all suggestions...

There is no magic number and a lot depends on your particular chickens adn how much air mvmt there is in the coop... but generally it is safest to keep humidity below 85% or so, you certainly don't want it in the 90+ range.

I know there is a similar post below this but my specific question is what can I do to minimize or release excess humidity in negative degree temps? I have core drilled holes in the tops of the coop but still get condensation/frost on the door which is all windows. also, the bedding (shavings) seems to get damp and frozen to the vinyl floor.

Drilled holes are not generally sufficient ventilation, because they are so small. You need to be thinking in terms of square FEET of ventilation, not square inches. (Note that a 3" diameter circle is only 7 square inches; there are 144 square inches in one square foot)

If the bedding is damp enough to freeze into a crust, I would seriously consider replacing it with dry fresh bedding unless you have a WHOLE LOT of ventilation which it does not sound like you do.

A droppings board under the roost, the poo scraped and removed every morning, also goes a long way towards reducing indoor humidity.

You may get some frost on your windowed door no matter what you do, though, if it is rather warmer inside your coop than outside. This is not necessarily *indicative* of a problem, but it can *cause* a problem by making it real hard for your ventilation to remove sufficient water (since it remains bound on surfaces instead of in vapor form). If the window area is very large (you mention it is the whole door?) you might consider attaching bubblewrap over the whole surface of it for the winter, which in borderline situations can create enough insulation that you don't get the condensation forming there, yet it still allows 'reasonable' light thru the window.